Monday, August 31, 2009

Groundwater Use and Septic Recharge a Green Solution

It is a Common perception that Septic Systems are highly consumptive. However as studies by the USGS, North Carolina Division of Water Quality and the Dutchess County Water & Wastewater Authority have clearly shown, when designed for the correct densities and recharge rates, well (or even surface water) use combined with septic systems is highly sustainable and ecologically sound (Draper, 2006; USGS, 2002). Surface-water resources and groundwater treated in Septic onsite wastewater treatment systems are non-consumptive because they increase base flow into the watershed, and the water can be reused. Properly designed and managed traditional septic systems, alternative septic systems and clustered septic system are an effective method of waste disposal and trod lightly on the earth’s resources. According to the US EPA alternative septic systems, both single family and clustered, exceed the standards for sewage treatment plants and replenish existing groundwater systems, returning clean water to the earth’s water cycle. These alternative onsite systems can be more sustainable to the surrounding ecosystem than sewers and centralized waste treatment and are certainly less expensive for the homeowners in sparsely populated areas. However, the systems need to work properly and alternative systems with multiple tanks, compressors and various parts require consistent maintenance to continue working properly. Remember though, what goes into your septic system goes into the earth. Think carefully about the products you use to clean your house. Paint, solvents, gasoline, insecticides and poisons should never go down your drain. Every chemical you pour down your drain is buried in your yard. In a multitude of ways your yard is part of the earth’s yard.

The 2006 USGS study of water use and recharge in the Atlanta area (before the watering ban) found that average household indoor water use was 200 gallons per day and in the summer months the total water use increased to about 300 gallons per day including outdoor water use. Sustainability should be examined in light of that level of usage. The Dutchess County Water & Wastewater Authority commissioned a study by the Chazen Company at about the same time to better understand County-wide aquifer recharge rates and to provide guidance for setting sustainable development densities specifically related to the use of individual wells and conventional individual septic systems based upon average aquifer recharge. While the quantitative results of the study would apply to the soil types, rainfall and temperature ranges specific to the watershed studied, extrapolations can be made to nearby locations. The weather from New England to the Mid Atlantic to the South becomes warmer and wetter. Currently, average rainfall for New York is 39 inches per year while for Virginia it is more than 45 inches per year. The hydrologic soil groups present in New York are the same groups present in Virginia, but I would guess there is a higher concentration of C/D and D areas. The predominant area of the study, Wappinger Creek is C and C/D soil category. Chestnut Lick, a large creek, behind my house has similar soil hydrologic properties, but the soils on the acres surrounding the house contain a higher proportion of clay. This may be natural or due to the excavation associated with development of the lot and road.

Shallow groundwater flow, or groundwater runoff, intercepts the land surface, feeding springs, and creeks and seeping back into the surface waters as the perennial flow or streams, rivers and other freshwater bodies such as swamps, lakes and ponds. Deep groundwater flow also known as groundwater runout, does not intercept the land surface, flowing instead directly into the ocean. Of all the Earth’s water, only 3% is estimated to be freshwater. Groundwater is estimated to be more than 30% of the freshwater. Precipitation is the source of all groundwater, both shallow and deep. Hydrology is a young science and the modeling of the water cycle is not complete. The recharge rates and water cycle of the shallow groundwater in humid environments is much better modeled and understood than the deep earth sources of groundwater. So, while the entire water cycle is essential to man’s survival, only the shallow cycle will be discussed here.

Aquifer recharge consists of the portion of rain and snow (mostly rain in Virginia) that seeps through the soil to the saturated water zone, the aquifer. Another form of recharge is interflow which is infiltration water that flow along clay and bedrock layers, and roots to reach surface stream without entering the aquifer. Only the aquifer recharge supports wells and septic system dilution, while both recharge and interflow support the surface water supplies. In watersheds with high clay content in the soils a large portion of the rains is lost in runoff creating seasonal streams and high creek and river flow during the spring and fall rainy season. The average daily aquifer recharge (from rain and snow only excluding septic recycling) for Soils C, C/D and D in Prince William Virginia are estimated 326-583 gallons per acre. It is essential in a sustainable system that the groundwater level be maintained with recharge and adequate surface water is supplied to maintain the ecology even during drought years. My property totals more than 10 acres and our total indoor and outdoor household water usage was clocked during the early summer at between 100 and 150 gallons a day. We do not water our garden; trying to plant only what will thrive in the natural environment unaided. Virginia gets plenty of rainfall and it seems silly to plant anything that requires irrigation. Thus, not only is my septic system non-consumptive, the recharge rate vastly exceeds our water usage (and hopefully our neighbors since our water supply is dependent on total demand and recharge of the aquifer).

Though as demonstrated by the USGS studies, septic is a non-consumptive use of water, it is important that the septic system is designed and operated in a way that protects the environment. Whatever goes down the toilet or the drain goes into the earth. (See Septic Systems and the Ecologically Sustainable Life.)The Dutchess County report used nitrate concentrations at half the drinking water level as a proxy to achieve adequate dilution and natural attenuation of all contaminants. Historically, horizontal and vertical setbacks were developed without consideration of the dilution for wastewater components like nitrate, pharmaceutical residue, caffeine and other substances we humans consume, process or produce. The NY Department of Health separation distances were assumed (and these are almost identical to the Virginia setbacks), but the overall regional density of septic systems was examined to ensure that groundwater resources would not be overwhelmed by the total load of contaminants. The density recommendations were developed based on the nitrate concentration in traditional septic wastewater. Nitrate was used as a proxy because all humans produce about 10 pounds of nitrate per year, it does not easily break down and there is a drinking water standard. The target concentration was half the drinking water level to ensure all outcomes are safely below the standard since household size varies tremendously.

The Dutchess County study and the NC study found that overall average density of on-site waste disposal should not exceed one unit per 2-3 acres for an average size house to ensure water quality and recharge in groundwater supplies. The controlling factor in minimum lot size requirements in the northeast appears to be maintaining water quality, not groundwater recharge. Adequate dilution, soil filtration and time are necessary to ensure sustainable water quality. An interesting point is that it is not cost effective to install central water or waste disposal on parcels larger than about a half acre, since the cost of the piping (line connections) between parcels becomes much too high. Clustered or conservation subdivisions can be built, but need to maintain the overall density by maintaining open space. Those who live in dense population areas might want to look to the sustainable ideas of Adam Matthews and Siobhan O’Connor in Good magazine, the water issue, though, I find their idea of a composting toilet in any environment to be really scary from a public health perspective.

Thursday, August 27, 2009

The Cost to the Homeowner of Septic Regulations in Virginia

On Thursday, August 20th, 2009 the fourth and final meeting of the Virginia Department of Health “Alternative On-site Sewage Systems Emergency Regulations Ad Hoc Committee” took place. I have participated in the process representing the homeowner’s point of view. Legislation approved in 2009 (HB 2551, Acts of Assembly, 2009, Ch 220) requires the Board of Health to promulgate emergency regulations to establish performance requirements and horizontal setbacks necessary to protect public health and the environment for alternative on-site sewage systems. The regulations must go into effect no later than April 6, 2010 and must also contain Operation and Maintenance requirements for alternative on-site sewage systems.

Today, alternative on-site septic treatment systems are designed to be state of the art, meeting EPA's treatment standard one. This exceeds the standards for sewage treatment plants and replenishes existing groundwater systems. These alternative on-site systems can be more sustainable to the surrounding ecosystem than sewers and centralized waste treatment and are certainly less expensive for the homeowners in sparsely populated areas. However, the systems need to work properly and these newer alternative systems with multiple tanks, compressors and various parts require consistent maintenance to continue working properly. The US EPA has found that adequately managed decentralized waste water treatment systems are a cost effective long term option for meeting public health and water quality goals in less densely populated areas. So, let’s manage them correctly, exactly the goal of the Virginia legislation. What will this cost the homeowner? Of course the final cost will be determined by the exact scope of the regulations, but to give you some idea of what this means to your pocket book I have spent some time pricing out the services.

Loudon County currently requires annual inspections and maintenance contracts for alternative systems, so that at least in Northern Virginia, there is a market for the various services. In addition, § 32.1-164 of the Code of Virginia requires Virginia Board of Health to begin an O&M program for alternative septic systems that is based on the manufacturer’s operation and maintenance instructions, local requirements, or state rules and policies whichever is most stringent. These requirements went into effect on July 9th 2009 and remain in effect until final regulations for O&M of alternative systems are in place. Thus, throughout the state there are septic installation and service companies that have been certified by various manufacturers and currently offer the inspection and operation and maintenance service. Though prices seem to be higher for Northern Virginia and Virginia Beach than other areas I checked, prices from a qualified firm tend to range from $400-$680 annually with a 25% discount available if a group of neighbors get together to negotiate a contract or the HOA negotiates contracts for 10 or more homes. Travel time is a big factor in overall expenses to the service company. That expense translates into an annual operating expense of about $40-$50 a month for sewage. If you have an alternative septic system, make sure that the firm you deal with is certified by either the county or the manufacturer to service your type of system. I did have one firm that quoted a price of $1,750 annually!! When I questioned the price, they told me that I had a “buried tank” that would have to be dug up each year. This was nonsense; I have three tanks with surface ports that can be plainly seen and the man was standing in my yard when he handed me the quote. There are no four tank systems.

There is another area of potential expense that was discussed at the final meeting of the Virginia Department of Health “Alternative On-site Sewage Systems Emergency Regulations Ad Hoc Committee,” should there be end of pipe monitoring for single family home systems. This end of pipe monitoring includes several related items: laboratory sampling of end of pipe effluent, laboratory sampling of groundwater, and field sampling/testing. Let me address groundwater first, it is impractical under any circumstance. Sampling of groundwater for compliance monitoring is impractical because without installing at a minimum three monitoring wells and potentially many more it would be impossible to determine if a groundwater aquifer were contaminated and the costs of not only the well installation and sampling but water analysis would be astronomical. In addition, leaving monitoring wells on-site in perpetuity for ongoing sampling would open potential pathways of contamination to the groundwater.

For end of pipe sampling there was some support for the requirement for single family homes from the VDH and some of the engineering community. As Anish Jantrania of Northwest Cascade put it “I would argue that the regulatory requirements for O&M should be set such that they do not become the driver in decision-making process for selecting which approach to take for designing land-based effluent dispersal system. This mainly applies to the requirements/frequencies of effluent quality sampling and lab analysis. If effluent quality sampling is going to be required at some frequency for large systems then it must be required at a reduced frequency for single home system!” The VDH was attracted to the idea of sampling end of pipe as a method to develop a database of the functioning of the systems. As someone who actually went through the expense of sampling the third tank in my alternative septic system just to find out if the system functions properly I am well aware that the cost could be between $350 and $400. The actual analysis costs $240 but to have a company come out and draw the sample according to protocol, ice and deliver the sample to the laboratory for analysis can cost up to $150 more. I thought long and hard about that expense, but in the end I wanted to make sure that at least on a typical summer day my system was operating within design parameters. It was. Since there are no regulatory consequences for single family alternative systems sample results adding an expense to the homeowner to level the playing field or collect data was something I argued against at the meeting. There are potentially economies of scale in clustered systems and that would help level the playing field.

The group did not vote in favor of routine end of pipe sampling for single family homes for approved technologies. However the group was in favor of field sampling. Where field sampling and laboratory analysis was thought to be potentially beneficial was for approving new technologies into a state or for "unproven" or unique designs. Having to routinely sample individually engineered designs would put these systems at a disadvantage. Joel Pinnix made a very powerful argument for the effectiveness of the individually engineered systems and their potential superiority for the out of the box or off the shelf systems. Then went on to say “There is no place in a regulatory process for data gathering. If VDH wants to gather data for informational purposes, then they should do so by getting a grant and performing a scientific study. There is certainly a role for VDH to conduct or fund studies of alternative systems, but the Emergency Regulation is not an appropriate mechanism to gather data for informational purposes.” Colin Bishop of BMN-US pointed out to me in a communication yesterday there is a role for field sampling and possibly laboratory sampling in extreme circumstances. Operation and Maintenance service providers will routinely perform field checks such as Dissolved Oxygen, Turbidity, pH, etc. with field testing equipment. Field tests can be performed for just a few dollars and are extremely helpful in identifying a problem if a system seems "upset" and there is a need further troubleshooting.

Monday, August 24, 2009

Commonwealth of Virginia Emergency Regulations for Alternative Septic Systems Part 4

On Thursday, August 20th, 2009 the fourth and final meeting of the Virginia Department of Health “Alternative On site Sewage Systems Emergency Regulations Ad Hoc Committee” took place. I have participated in the process representing the homeowner’s point of view. Legislation approved in 2009 (HB 2551, Acts of Assembly, 2009, Ch 220) requires the Board of Health to promulgate emergency regulations to establish performance requirements and horizontal setbacks necessary to protect public health and the environment for alternative on site sewage systems. The regulations must go into effect no later than April 6, 2010 and must also contain Operation and Maintenance requirements for alternative on site sewage systems. It is the goal of the Virginia Department of Health to promulgate the regulations in the third quarter and have them go into effect before the end of the year.

For the final meeting, members of the Ad Hoc Committee and the Department of Health made a full court press to pull together and wrap up the process. I for one found the meeting and the materials provided both thought provoking and satisfying. The Committee was able to come to a consensus thanks in a large part to the able facilitation by Bruce Dotson of CSR of the University of Virginia. All the loosely controlled discussions of various people’s point of views allowed the Committee members to develop an appreciation of other perspectives to enrich our understanding of the difficulty of the problem. This broadening of our viewpoints allowed us to be accepting of the majority opinion for the scope of the performance requirements and horizontal setbacks necessary achieve our goal. Hopefully, the suggestions of the Committee will be incorporated into the emergency regulations.

To a large extent the final vote of the Committee was impacted by the materials provided by other Committee members. Colin Bishop of Bord Na Mona Environmental Products provided some research articles that clarified, for me, the issues on horizontal setbacks despite the reasonable arguments for a narrower limit for engineer designed systems. Most influential in my thinking was some of the older, but still valid research from the RS Kerr Environmental Research Laboratory in Ada, Oklahoma. When I worked for the US EPA this was the laboratory providing the groundwater research that was used in the development of groundwater models and regulations. The study by Marylynn V. Yates points out that septic tanks contribute 800 billion gallons of waste water per year to the subsurface. The study found that the most important factor influencing groundwater contamination by septic tanks is the density of systems in an area and the distance to the contamination point. It is as simple as that. The fewer systems per square mile the less chance of contamination. Distance from a septic system, the so called horizontal set backs are the final protection from harm especially for those of us who obtain our drinking water from private water supplies.

In a memo, Merle Fallon and a co-author who are very familiar with Department of Environmental Quality regulations pointed out that the Virginia Department of Health regulations for clustered system should be compatible with the current DEQ regulations for operators of alternative on site sewage systems. The rules for the operators should be substantially the same. In addition they point out that a single set of horizontal set backs will provide consistency. Though secondary treatment levels provided by alternative on site systems might allow the reduction in setback in some circumstances, using the standard setbacks allows for simplicity and provides a secondary degree of protection. When the Committee voted (thought it was in reference to engineered designs horizontal setbacks) it was in overwhelming support that the horizontal setbacks from drinking water, property lines and surface water were to be maintained for single family alternative septic systems. The balance of providing a reasonable secondary level of protection, especially in environmentally sensitive areas, defined as proximity to surface and drinking water supplies while allowing development and use of property was achieved. At least for me the logic of the argument presented by Marcia and Merle and information provided by Colin was most convincing. Virginia’s water supply is one of its great assets and should be carefully protected to ensure that the Commonwealth can continue to grow and prosper in years ahead.

Thursday, August 20, 2009

The Diminishing of Groundwater Aquifers

On earth, groundwater is ubiquitous and like all water on earth it comes from precipitation that percolates through the soil until it reaches the zone of saturation. Though groundwater is everywhere the quantity and usability of groundwater varies from location to location based on geology and precipitation. The rate at which precipitation percolates through the soil to resupply the groundwater is called the recharge rate and also varies for site to site. Groundwater is water that fills the cracks and pores of rocks and sediments that lie beneath the surface of the earth saturating those materials. Gravel, sand, sandstone, or fractured rock have large connected spaces that allows water to flow through them allowing an aquifer to form. Impervious layers of clay and bedrock prevent ground water moving from one space to another. Rain and snow pass through the soils, rocks and sediments to constantly make more ground water. In order for the water supply to be sustainable, groundwater cannot be withdrawn faster than it is resupplied.

Due to its protected location underground, most groundwater is naturally clean and free from pollution. Not understanding the nature of groundwater and the important role it plays in sustaining life, we have over used it and abused it. In the past when we buried fuel tanks, industrial and household waste at landfills, poured solvents out into the dirt, used excessive amounts of fertilizer, had uncontrolled waste from animal feedlots we were contributing to the contamination of groundwater. Homeowner disposal of chemicals, treating a home for termites, excessive use of fertilizers (even organic), and malfunctioning septic systems can all impact onsite groundwater quality and potentially down gradient sites.

In addition to contamination we can damage groundwater supplies by pumping groundwater beyond its recharge rate literally using up this valuable resource. Fresh, potable, uncontaminated water is not unlimited. According to the Stockholm International Water Institute, about a fifth of water used globally is groundwater and that portion is growing. California has for several generations been a leader in water management, moving water from where the rain and snow falls to where the water is needed in what was hoped to be a reliable and sustainable way. Water banking is used within the state to reallocate water from lower use areas to recharge the aquifer in high demand areas. Through tight management techniques, California was until recently able to supply the state with water in a sustainable way. Periodic droughts have historically plagued the system, now though, less than average rainfall for more than one year seems to be all it takes to upset the cart.

Recent advances have made it possible to measure groundwater supplies using satellites. The orbiting satellites measure the gravitational pull of water below the earth’s surface and now are able to confirm that the groundwater level is falling in areas of India. Over the years the water table has fallen in California. While irrigation has allowed the world’s farmers to produce vastly increased amounts of wheat, rice and other staples. The demands of mankind for water to sustain life and to produce food have continued to grow with growing population. Internationally, both groundwater and surface water supplies are strained. In India the monsoon rains have been the weakest in five years and that is exacerbating demand for groundwater based irrigation. The India’s Central Ground Water Authority regulates the pumping from aquifers. Unsustainable pumping in some areas has resulted in a drop in the water table and sea water intrusion. Groundwater aquifers cross international borders and water rights and potable water supplies will become the crisis of the twenty first century.

Monday, August 17, 2009

California's Water Supply at the Breaking Point

As pointed out in the WSJ Opinion piece by Rep. Nunes California has the largest water storage and transportation system in the world. With 1,200 miles of canals and nearly 50 reservoirs, the system captures enough water to irrigate about four million acres and provide water to 23 million people. In many cases, water in this system is sold to communities by the federal government. The price for this water is not based on it’s value or scarcity, but on an arbitrary rate. Limited resources are allocated by the government. Without this extensive management system California’s limited water resources could not supply the state. California has for several generations moved the water from where the rain and snow falls to where the water is needed in what was hoped to be a reliable and sustainable way.

Ground water supplies which typically supply 40% of the state’s needs in an average year are carefully managed in the public supply wells so that the amount of water pumped out does not exceed the amount recharged over time. Water banking is used to reallocate water from lower use areas to recharge the aquifer in high demand areas. Much of the usable water in the state falls as rain and snow in the northern third of the state during the winter on the western slope of the Sierra Nevada Mountains. The cities of California and the irrigation demands of the San Joaquin Valley have grown to demand more than three quarters of the water available in the state. As population has grown California has developed the most complex water storage, transport and flood management system found anywhere in the world.

The Central Valley Project began in the 1930’s and was completed with the State Water Project in 1970’s. While these projects were considered engineering marvels at the time and have provided the fluid of life to the state’s economic growth, they were not built to meet all the demand placed on them today. Nor were they built with the Sacramento and San Joaquin River Delta’s current environmental issues in mind. To a large extent those environmental problems have been caused by water diversions, invasive species and loss of habitat to development. We seem to have reached the breaking point for the state despite the fact that California reservoirs have received 80% of their normal amount of water and precipitation in the northern Sierras has been 95% of its yearly average this year.

According to Rep. Nunes, sections of the San Joaquin Valley is being transformed into a dust bowl. Thousands of acres lay fallow, while almond, olive, plum trees and grape vines are being left to die in the sun. Tens of thousands of people have lost their jobs because of the depression level drought in some sections of the Central Valley. This is a regulatory-mandated drought. Almost all water in California is delivered so where to deliver it, is a choice of the state water agencies. The needs of California have been increased. The 1973 Endangered Species Act requires that the government take steps to save endangered species. In California, that's meant diverting vast sums of water into rivers and streams to prevent salt water intrusion, protect fish while allowing the farms without private goundwater supplies to go dry. The limitation of the water supply these past couple of years have forced federal authorities to decide who to serve, fish or farmers. In California, there isn't enough money or water to go around this year,. The federal government has plans to divert more water into the Delta and the San Francisco Bay. California is sending out glossy brochures about the water supply with directions and encouragement to conserve water.

There simply is no longer enough water. Trees are being stumped in hopes of saving orchards. Individual farmers are pumping what groundwater they have beyond the recharge rate to save their investment in trees and vines or just survive. The state can not easily prevent this pumping. The NY Times reported that due to the increasing drought in California farmers have been pumping more groundwater to irrigate their crops, lowering the level of the groundwater. As a result the state has begun to try and collect data on groundwater supplies with an eye to regulation. Water is not sold at market prices. In most communities water is still less than a penny per gallon at the tap. Encouraging individuals to conserve is a viable method of reducing demand. Raising the price of water might encourage this behavior. Food prices do not reflect the water subsidy, and the environment is not paying for the water.

The economy of California based on control of the water and the allocation is based on regulatory decisions. The water supply has failed to match the demand for a product with no real price, and the economy of the state has also failed. The demand for and use of water must be reduced or the supply increased. I leave it to you to determine the best way to do that. Reduce the acreage of cultivated land? Reduce the population? Ration water to all citizens? Reduce the resources to maintain the environment? Or will the state find the resources to build desalination plants? Whatever solution California chooses, will be a game changer for California and the American economy. The people of the state will be poorer because resources will now be diverted to provide more water or less water will be available for agriculture. America will be poorer, California represents 20% of the US economy.

Thursday, August 13, 2009

Geothermal Heat Pumps

The most effective type of heat pump is the geothermal heat pump, GHP. It doesn't create heat by burning fuel, like a furnace does. Instead, in winter it collects the Earth's natural heat through a series of pipes, called a loop, installed below the surface of the ground or submersed in a pond or lake. As you may have experienced in a cave, the temperature six feet beneath ground surface is cooler in summer and warmer in winter than the ambient temperature. Using this temperature as its source the GHP can operate within its most efficient range. In winter, fluid circulates through the loop and carries the heat to the house. There, an electrically driven compressor and a heat exchanger concentrate the Earth's energy and release it inside the home at a higher temperature. Ductwork distributes the heat to different rooms. In summer, the process is reversed. The underground loop draws excess heat from the house and allows it to be absorbed by the Earth. The system cools your home in the same way that a refrigerator keeps your food cool by drawing heat from the interior, not by blowing in cold air.

The geothermal loop that is buried underground is typically made of high-density polyethylene, a tough plastic that is extraordinarily durable but which allows heat to pass through efficiently. The fluid in the loop is water or an environmentally safe antifreeze solution that circulates through the pipes in a closed system. Earliest systems were open loop, but those could impact the groundwater supply and are not used as much today. There are two types of closed loops used to provide constant temperature to the GHP. Horizontal ground loops are usually the most cost effective when trenches are easy to dig and the size of the yard is adequate. Workers use trenchers or backhoes to dig the trenches six feet below the ground in which they lay a series of parallel plastic pipes. They then backfill the trench. Fluid runs through the pipe in a closed system. A typical horizontal loop will be 400 to 600 feet long for each ton of heating and cooling.

The vertical loop is used where there is little yard space, when surface rocks make digging impractical, or when you want to disrupt the landscape as little as possible. Vertical holes are typically 150 to 450 feet deep and contain a single loop of pipe with a U-bend at the bottom. Each vertical pipe is then connected to a horizontal underground pipe that carries fluid in a closed system to and from the indoor exchange unit. Vertical loops are generally more expensive to install, but require less piping than horizontal loops because the Earth's temperature is more stable farther below the surface.

Geothermal heat pumps (GHPs), more accurately called ground-source heat pumps, have been proven capable of producing large reductions in energy use and peak demand in buildings. Although the U.S. was once the world leader in GHP technology and market development, European markets now absorb 2 to 3 times the number of GHP units annually as do the U.S. domestic markets. In 2007 the Intergovernmental Panel on Climate Change identified the building sector as having the highest green house gas emissions, but also the best potential for dramatic emissions reductions. In their report GHPs were specifically identified as a solution that is economically feasible under certain circumstances‖ in continental and cold climates. Their report cited cases where total electricity use decreased by one third and heating energy use by 50 to 60 percent.

Tax credits for home and business owners investing in GHP systems were enacted in October 2008 through 2016 and increased in the stimulus plan of 2009. Hopefully these tax credits will help GHP achieve wider market acceptance despite its large upfront capital costs. The largest hurdle to the widespread adoption of GHP technology seems to be the capital cost for initial installation. The outside portion of the GHP system can be half or more of the overall GHP system cost (and equal to the total cost for a traditional furnace and air conditioner). The technology while economically viable, is little known or understood and has suffered from the high upfront and installation costs. If the costs of the exterior coils were excluded, GHP systems have about the same price as competitive alternatives. In addition, due to the lack of demand, there are few design and installation firms in the market.

Buildings, both residential and commercial, account for about 40 percent of primary U.S. energy consumption, 72 percent of U.S. electricity consumption, 55 percent of U.S. natural gas consumption, and significant heating oil and propane consumption in the Northeast. While industrial use of electricity has been flat for about 15 years, electrical use to power commercial and residential building has grown by more than 50 percent since 1985. U.S. resources and investment have been deployed to build the infrastructure required to generate, transmit, and distribute electricity to serve that growth. Reducing the peak electricity demands for air conditioning and heating could alleviate peak demand on the electrical grid. Buildings present one of the best opportunities to economically reduce energy consumption and limit green house gas emissions. A recent study by McKinsey & Company study performed for the Department of Energy found that reducing the consumption of energy in buildings is the least costly way to achieve large reductions in carbon emissions.

A study by the U.S. Environmental Protection Agency (EPA) comparing the major HVAC options for residential applications determined that GHPs were the most energy efficient and environmentally benign option. Yet only about 60,000 units are installed each year in the combined new built and retrofit market. This languishing of the market is attributed to several federal policy lapses. A program at the DOD ran for several years in the late 1990’s intended to increase use of GHPs in federal buildings. This program’s authority was allowed to lapse. Although DOD took the initiative to restore the program 14 months later by then much of the GHP project pipeline had diffused away. A second policy mistake damaging to federal agency use of GHPs occurred in 2005 when the Energy Policy Act defined renewable energy that counted toward agency renewable goals as power generation only, excluding thermal forms of renewable energy such as GHPs. No lobbyists were paid to identify this oversight. Federal utilization of GHPs might have created the critical mass for the market; instead it was once more forgotten.

The basics of GHP technology have changed very little over the decades but awareness, understanding, and acceptance of the systems is limited. The systems are truly misnamed, GHPs are often confused with geothermal power production, in which the extreme heat of subsurface geological processes is used to produce steam, and ultimately to generate electricity. GHPs are also sometimes confused with the direct use of geothermal heat in which greenhouses, aquaculture ponds, and other agricultural facilities are heated using lower-temperature sources such as hot springs. Ground source heat pumps can be used economically anywhere and utilize the earth stored solar energy to function. There are at least 16 manufacturers of GHPs in the United States that participate in the residential and commercial markets. The GHP market began to develop in the late 1970s, and has had its ups and downs due to the cyclic nature of the buildings industry and volatility in government and utility support and the prices of competing forms of energy. The current tax incentives and awareness of US energy consumption may serve as an opportunity for the GHP market to achieve critical mass.

Monday, August 10, 2009

Heat Pumps

There are many different kinds of heat pumps, but they all operate on the same basic principle of heat transfer. Heat transfer means that rather than burning fuel to create heat, a device moves heat from one place to another.As with many technologies that we use in every-day life; the basic principles of how a heat pump works are simple. Heat naturally flows from a location with a high temperature to a location with a lower temperature. A pie taken from a hot oven and set on the counter will cool. If air is blown past it, it will cool faster. A heat pump uses a small amount of energy to switch that process into reverse, pulling heat out of a relatively low-temperature area, and pumping it into a higher temperature area. In a heat pump, this heat is transferred from a heat source (for example, the ground or air) into a heat sink (for example, your home).

As seen above, one of the most common types of heat pumps is the air-source heat pump, which takes heat from the air outside your home and pumps it inside through refrigerant-filled coils. Inside this basic heat pump, you'll find two fans, refrigerator coils, a reversing valve and a compressor. There are usually two physical units, one indoor and one outdoors they contain the compressor and heat exchanger. The direction of heat flow may be reversed. The reversing valve switches the direction of refrigerant through the cycle and therefore the heat pump may deliver either heating or cooling to a building. The effectiveness of a heat pump is based on the temperature difference between the source and the sink and which cycle it is in. Heat pumps are more effective for heating than for cooling if the temperature difference is held equal. This is because the energy used to power the compressor is largely converted to useful heat when in heating mode and released into the house as extra heat. During the cooling cycle, the condenser is normally outdoors, and the compressor's dissipated work is rejected rather than put to a useful purpose.

The most common types of heat pumps work by utilizing the physical properties of the refrigerant, a fluid that can reach a sufficiently high temperature when compressed, since the laws of nature prevents heat from flowing from a cold fluid to a hot heat sink. The working fluid, in its gaseous state, is pressurized and circulated through the system by a compressor. On the discharge side of the compressor, the now hot and highly pressurized gas is cooled in a heat exchanger (the indoor unit), which is a series of coils where the hot fluid comes into contact with cooler air, until it condenses into a high pressure, moderate temperature liquid. The condensed refrigerant then passes through a pressure-lowering device like an expansion valve. This device then passes the low pressure, (almost) liquid refrigerant to another heat exchanger, the evaporator where the refrigerant evaporates into a gas via heat absorption. The refrigerant then returns to the compressor and the cycle is repeated.

All our surroundings, even a block of ice, has heat. The purpose of a heat pump is to absorb heat in one place where it is plentiful, then to transport and release it in another location where it can be used for heating. Useful heat can be found in the air outdoors, in the ground, and is present in water, rivers, lakes and the sea. Even on the coldest winter days, sufficient heat is present to warm our homes and buildings. All we have to pay for is the machine to operate which uses less energy than fueling a furnace. Heat pumps are more effective for heating than for cooling if the temperature difference is held equal. Heat pumps are most efficient when the temperature differential is moderate; with a temperature differential less than 20-30 degree range the system would run optimally and be most cost effective. Air heat pumps have typically only been used in moderate climates because their efficiency declines the larger the temperature differential between desired temperature and source temperature. However, there are other types of heat pumps that can overcome these problems.

Thursday, August 6, 2009

Thoughts from the Environmental Movement

The environmental movement has reached middle age. The widespread acceptance of the validity of the environmental movement was marked in 1970 by the first Earth Day in April and by the founding of the US EPA in December of that year. Yet, 1970 was not the beginning of the environmental movement that happened in the 1950’s and 1960’s in the height of the post war industrial era. Fires occurred on the Cuyahoga River in 1868, 1883, 1887, 1912, 1922, 1936, 1941, 1948, and in 1952. The fires are believed to have been caused by vast oil slicks on the river. The 1952 fire caused over 1.5 million dollars in damage, but today we recall only the small and short lived fire of 1969. The time was right, the environmental movement had had been embraced by the country. On August 1, 1969, Time magazine reported on the fire and on the condition of the Cuyahoga River. The magazine stated:

“Some River! Chocolate-brown, oily, bubbling with subsurface gases, it oozes rather than flows. "Anyone who falls into the Cuyahoga does not drown," Cleveland's citizens joke grimly. "He decays". . . The Federal Water Pollution Control Administration dryly notes: "The lower Cuyahoga has no visible signs of life, not even low forms such as leeches and sludge worms that usually thrive on wastes." It is also -- literally -- a fire hazard.”

When we see today’s environmental issues and concerns we are alarmed and forget the dreadful state of the environment 40 years ago. Not only was the Cuyahoga in terrible shape, countless rivers and streams were virtually dead zones. We have come so far that even with the US population increasing from 200 to 300 million people our air is cleaner, our water is cleaner and our soils less contaminated. We have much to celebrate and much work yet to do.

A family of wild turkeys has parked themselves in our yard and the back meadow is filled with black birds. While trying to figure out if the black birds are crows, ravens or black birds I am reminded of the bird watcher and author Rachel Carson. Her book, Silent Spring, is widely credited as beginning the environmental movement. From the US EPA history:

“(M)any environmental ideas first crystallized in 1962. That year saw the publication of Rachel Carson's Silent Spring, first in serial form in the New Yorker and then as a … best seller. This exhaustively researched, carefully reasoned, and beautifully written attack on the indiscriminate use of pesticides was not exactly light reading. Yet it attracted immediate attention and wound up causing a revolution in public opinion. Skeptics then and now have accused Carson of shallow science, but her literary genius carried all before it. Followers flocked to Carson's cause--rendered all the more sacred by her premature death in 1964. Suddenly, everywhere people looked, they saw evidence of nature's spoilation. Concern over air and water pollution spread in widening eddies from the often-forgotten core of the movement: a highly detailed and intellectually challenging book about commercial pesticides.”

It is difficult for someone of my age and inclinations (having worked for the US EPA in the 1970’s) to think of DDT without thinking of Silent Spring. Though it is often thought that Carson was calling for the elimination of all pesticides, Carson had made it clear she was not advocating the banning or complete withdrawal of helpful pesticides, but was instead encouraging responsible and carefully managed use, with an awareness of the chemicals' impact on the entire ecosystem. As Eric Hoffer points out in his book, “True Believer” mass movements can never be moderate and rational they attract followers by the prospect of sudden and spectacular change. We are a nation of over sprayers. We figuratively and literally take the Raid can and spray a stream of bug spray at the offending specimen until we kill it by poisoning or drowning. Moderate, responsible action seems impossible for us, but that is the skill we must learn as responsible stewards of this earth and as humane and concerned citizens of the planet. We must balance concern for the earth as measured by whatever index suites your world view with the needs of the lesser developed world to escape poverty and disease. What is the point of saving the earth if not for mankind? For an upbeat look at progress made in the fight for a cleaner planet see “Index of Leading Environmental Indicators, Fourteenth Edition” by Steven E. Hayward. It is worth reading in these challenging times.

Monday, August 3, 2009

Pesticides and Ornamental Gardens

On Thursday, July 30th the Wall Street Journal published an article by Gwendolyn Bounds entitled “Death by Mint Oil: Natural Pesticides.” As Ms Bounds points out more and more pesticides, herbicides and insecticides derived from naturally occurring substances are now commercially available. Some of the more natural pesticides were introduced in the 19th century, and are based on, pyrethrum which is derived from chrysanthemums, and rotenone which is derived from the roots of tropical vegetables. Others like boric acid (used to kill amongst other pests termite colony invasion inside homes and ant hills) and soap salts are just older and though modesty less effective are believed to be far less toxic. These older, naturally occurring chemicals are a step back, but believed to be even safer than the new generation of herbicides developed during last quarter century encouraged by the US EPA. Those newer herbicides were applied at much lower levels, broke down more quickly in the environment and were less toxic to animals. The new generation of herbicides was based on sulfonylurea and imidazolinone. Now it seems that the degradation products of these new herbicides are far more persistent in the environment that originally believed or hoped and we are looking once more at older, natural solutions.

Pesticide' is a broad term, covering a range of products that are used to control pests. The slug pellets, ant powder, weed killers, and rat and mouse baits that you may use in your everyday life are all pesticides. Other pesticides you may have heard of including: insect killers (insecticides), mould and fungi killers (fungicides), weed killers (herbicides), slug pellets (molluscicides), plant growth regulators, bird and animal repellents, and rat and mouse killers (rodenticides). Often people only think of pesticides as chemicals, but they include a very large range of different types of products. Some as described above are natural, while many are altered versions of natural chemicals.

In Canada there is a growing movement to ban the use of pesticides for ornamental use. Town by town, Provence by Provence bans are appearing. Ontario and Quebec have banned the pesticides use for cosmetic purposes on lawns, vegetable and ornamental gardens, patios, driveways, cemeteries, and in parks and school yards. There are no exceptions for pest infestations (insects, fungi or weeds) in these areas, as lower risk pesticides, biopesticides and alternatives to pesticides exist. More than 250 pesticide products are banned for sale and over 95 pesticide ingredients are banned for cosmetic uses. Pesticides, including herbicides, insecticides, fungicides, and rodenticides, used to simply prevent blemishes and other imperfections on private and public lands are referred to as the cosmetic (or ornamental) use of pesticides in these regulations. The question is should we be following the Canadian lead in this?

Though there has been no direct evidence linking pesticides with the exception of nitrogen to diseases in humans, an increasing number of health and environmental groups are claiming that these chemicals do indeed impact human health. A wide range of chemicals are used to treat everything from pests to mold in household gardens. One of those is 2, 4-D, used by cereal crop producers and commonly found in household weed killers. It has been the subject of an extensive study by Health Canada which determined that, when used properly, it is safe. Organizations like the Sierra Club and the Canadian Cancer Society, which strongly support a ban on cosmetic use of pesticides and herbicides, disagree. However, no specific research linking the currently used ornamental pesticides to disease in humans was found.

The only documented study to find a disease link to 2,4-D was done in the United States, a 1991 National Cancer Institute study examined dogs whose owners' lawns were treated with 2,4-D four or more times per year. The study found those dogs had double the risk of developing canine malignant lymphoma than dogs whose owners do not use the herbicide. Overall, it appears that the Canadian ban on cosmetic use of herbicides and pesticides is based on an emotional and logical belief that cchildren may be more at risk of developing health problems from pesticides because:

  • Their activities lead to more exposure e.g., playing in the grass, putting their hands or toys in their mouths.
  • They are closer to the ground and breathe in higher amounts of pesticides.
  • Proportional to their weight, they breathe in more air and consume more food and drink than do adults.
  • Their immature metabolic systems cannot break down toxins as effectively as adults.
  • Their bodies are rapidly growing and developing and potentially impacted more strongly by endocrine disruptor effects.

While I certainly do not know if a ban on ornamental use of pesticides will prevent disease in children, I wonder what the downside of reducing use would be. (For full disclosure purposes I have the third to worst lawn in my neighborhood, I apply no chemicals to my lawn and never water. However, I do hope to improve the lawn by aerating and over seeding annually and applying my compost. So far, not so good despite soil analysis that showed decent soil composition.)